A flexible engaging delivery device for delivery of a vaso-occlusion flexible engaging structure to a vascular target site via a catheter is disclosed comprising a catheter having a lumen and an introducer disposed within the catheter. The introducer comprises an outer sleeve, a shaft, and a wire that is slidably movable within the shaft. A wire tip is permanently connected to the wire, wherein the wire tip is adapted to contact a matted portion of the vaso-occlusion flexible engaging structure and is used to deliver said flexible engaging structure from said flexible engaging device to a vaso-occlusion target site.
In a variety of medical procedures, a physician may need to occlude vessels in order to contain bleeding or reduce the risk of hemorrhaging.
There are a variety of devices that have been developed to occlude blood vessels. One of these employs a catheter to deliver one or more vaso-occlusion coils to a vascular target site. The vaso-occlusion coils are typically platinum or other surgical-metal coils that are delivered via a vascular catheter. Typically, the coil is placed in a linear condition in the catheter, and is pushed from the end of the catheter by a pusher wire. As the coil exits the delivery device it assumes a relaxed, convoluted shape at the vascular site.
The coil may be deployed simply by ejecting it from the distal end of the catheter. However, this technique may be unsatisfactory where it is desired to better position the coil in the vessel once it has been ejected from the catheter and has assumed its convoluted shape. To overcome this problem, various release mechanisms have been proposed to allow for positive release of the coil from the end of a pusher wire once the coil is properly positioned at the vascular site. Expandable jaw clamps and electrolytically erodible joints are examples of such mechanisms.
It would be advantageous to provide a coil delivery device and catheter assembly which provides the combined advantages of (i) a coil release mechanism that allows for simple coil loading and release, (ii) positive release once the coil is properly positioned at the target site, (iii) multiple reloading steps, and (iv) operable with coils having a variety of coil diameters.
The invention includes, in one embodiment, a coil-delivery device for delivery to a vascular target site via an inner-lumen catheter, an elongate, flexible vaso-occlusion coil having an end-region inner lumen. The device includes an elongate sleeve, perhaps a catheter, having proximal and distal ends and an inner lumen extending therebetween, and a wire slidably movable within said sleeve. The wire has a distal end region extending beyond the distal end of the sleeve, and a proximal end region that can be manipulated to move the wire between extended and retracted positions with respect to the sleeve""s distal end. A flexible engaging structure in the device extends between the distal ends of the sleeve and the wire, such that movement of the wire between its extended and retracted positions is effective to move the flexible engaging structure between extended and radially expanded conditions, respectively, in which the engaging structure is adapted to be received within and compressionally engage the lumen end region of the coil, respectively.
The engaging structure in the device may be braided, generally in the shape of a sock. The structure may be dimensioned, with such in its extended position, to be received in the inner lumen of a coil having an outer diameter as small as 15 mils, and with such in its expanded condition, to compressionally engage the lumen end region of a coil having an outer diameter as great as 35 mils.
In another aspect, the invention includes a coil-delivery assembly for delivery of at least one, and preferably a plurality of vaso-occlusion coils to a vascular target site. The assembly includes (a) a catheter having proximal and distal ends, and an inner lumen extending therebetween, (b) an introducer for holding a vaso-occlusion coil in a substantially linear condition, and (c) a coildelivery device of the type described above. The introducer may have an end region adapted to be mated with the proximal end of said catheter, for transferring a coil from the introducer into the catheter. The assembly allows a coil to be frictionally and releasably engaged by the wire, with the coil held in the introducer, transferred from the introducer into and through the catheter, and released from the wire after being advanced across the catheter""s distal end.
Also disclosed is a method for releasably engaging a vaso-occlusion coil of the type having an end-region inner lumen. The method involves immobilizing the coil in a substantially linear condition in a tube having an open access end, inserting into the tube, a coil-delivery device of the type described above, and moving the wire in the device to its retracted position to compressionally engage the engaging member with the inner lumen of the coil.
These and other objects and features of the invention will become more fully apparent when the following detailed description of the invention is read in conjunction with the accompanying drawings.